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Clashes between token categories and token and ordinary categories #323

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andreasabel opened this issue Nov 13, 2020 · 1 comment
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Clashes between token categories and token and ordinary categories #323

andreasabel opened this issue Nov 13, 2020 · 1 comment
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@andreasabel
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error-reporting Concerning error messages BNFC gives LBNF Concerning the LBNF syntax and its checking
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2.9

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@andreasabel
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BNFC should reject this ambiguous grammar, rather than letting the backends crash:

Foo. L ::= L;

token L 'a';
token L 'b';
@andreasabel andreasabel added bug LBNF Concerning the LBNF syntax and its checking labels Nov 13, 2020
@andreasabel andreasabel added this to the 2.9 milestone Nov 13, 2020
@andreasabel andreasabel added error-reporting Concerning error messages BNFC gives and removed bug labels Nov 13, 2020
andreasabel added a commit that referenced this issue Nov 14, 2020
@andreasabel
[ #323 ] Complain if token category is defined twice
4185fd3 
Modified the definition of duplicatesOn to return the expected result.
@andreasabel
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The use of numeric prefixes in token names confuses BNFC:

Foo. Main ::= Main1 "fun";
token Main1 {"main"};

BNFC maps Main1 to Main in the AST definition, consequently, the parser contains type errors.

Solution: raise an error when the user defines a token name with a numeric suffix.

@andreasabel andreasabel self-assigned this Nov 15, 2020
andreasabel added a commit that referenced this issue Nov 15, 2020
@andreasabel
[ #323 ] disallow token names with numeric suffix
74e278c 
These will not be referenced correctly in the AST, because of coercion categories.
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error-reporting Concerning error messages BNFC gives LBNF Concerning the LBNF syntax and its checking
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